Is there some reason a loft in a 2nd floor flat has plasterboard seperating the section above the s from the rest of the loft? Maybe fire regulations?

[noseall]

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I'm struggling to find the bit that states after a number of years, the degradation of PIR means that it equals the efficiency of Jablite etc?

 

[freddiemercurystwin]

As mentioned PIR does drop off but the figures quoted by Kingspan etc are supposed to be the drop-off figures.